Sake Brewing Supplies, Information and Forum

I recently saw a section in “The Niigata Sake Book” labeled “How Much Sake Is Made out of 1 kg (2.2 lb.) of Rice” and thought this would make a nice topic to cover. I may later do a more in depth look at this but for now we will just get a good idea of the basics.

OK, so if we start with rice, water and some microorganisms how much sake will we get? Well, let’s start with brown rice as does “The Niigata Sake Book.” To make sake starting with brown rice the first thing that needs to be done is to polish the rice to a level needed for the type of sake we wish to make. To get down to the edge of junmai ginjo type sake we need to polish the rice to 60% or less. So let’s say we will mill the rice down to 60% of the original brown rice. That is, if we start with 1 lb. of brown rice this will leave us with 0.6 lbs. of white rice.

Now, for this there is a key ratio that needs to be understood. While this ratio will change somewhat for individual sakes, we will simply choose a reasonable example ratio for this analysis. The ratio of water used to the weight of rice added is around 1.3x, so that is what we will use. This implies the water needed for the fermenting mash will be 0.78 lbs. = 0.6 lbs x 1.3. The fermenting mash (the Moromi) will then be 1.38 lbs. = 0.6 lbs. rice + 0.78 lbs. water.

You may be thinking: what about koji? Well somewhere between 15 and 25% of the rice added is first used to make koji. It is this koji that supplies the needed enzymes to break down rice solids. The enzymes break carbohydrates into sugar and proteins into amino acids and peptides. So the koji is crucial in producing sake and determines how much of the rice remains as residue, lees or kasu once fermentation is complete.

The enzymes from koji will break down and liquefy all but about 30% of the original rice. In our case this amounts to 0.18 lbs. lees. Now, use a good press to separate the sake from the lees to get 100% separation. When we remove these lees from the Moromi we are left with 1.2 lbs. of sake = 1.38 lbs Moromi – 0.18 lbs lees. So, 1 lb. of rice can be used to produce 1.2 lbs of genshu sake. That is, full strength or cast strength sake; around 18 to 20% alcohol by volume.

Now we can convert this in to fluid ounces through the use of a few facts and a little math. A gallon of water weighs 8.35 lbs and is 128 fluid ounces. Alcohol weighs 0.785x water so a gallon of Alcohol weighs 6.55 lbs. Mixing volumes of 82% water and 18% alcohol gives a gallon that weighs 8.026 lbs. Given this, our 1.2 lbs of genshu sake has a volume of 0.149 gallons or 19.24 fluid ounces. So 1 lb. of rice produces about 19 ounces of genshu sake.

Most sake has water added to bring its alcohol level down to 16%. Sense we have 19 fluid ounces at 18% alcohol we have a total of 3.44 ounces of alcohol. To bring the percentage down to 16% we need a total of 21.5 ounces. Adding 1.5 ounces of water turns our genshu sake at 18% alcohol into standard sake at 16%. This means that 1 lb. of brown rice produces 21.5 fluid ounces of standard strength sake.

The analysis describe so far may be pretty close for commercial brewers but is overly optimistic for homebrewers. The missing element that needs to be included is the efficiency of pressing. The above assumes 100% efficient pressing. While somewhat optimistic for commercial brewers it yields completely unrealistic results for the homebrewer. To remedy this, we can include an efficiency factor by simply multiplying the result of the moromi minus the lees by an efficiency percentage. 100% yields the analysis result above. 65% brings the analysis results into agreement with homebrew practice.

OK, so what does this say about how much sake a homebrewer will get from a pound of brown rice? Well a typical batch of homebrew sake uses 10 lbs. of milled rice and 40 ounces of koji. But how much rice is needed to make 40 ounces of koji? That depends. For fresh koji, there is about 37 ounces of rice. However, for 40 ounces of dried koji 44.5 ounces of rice is needed. Anyway, depending on whether we assume fresh or dried koji will affect the results somewhat; between 3 to 4 percent.

Getting back to it, including koji, the typical homebrew sake uses roughly 12.5 lbs. of 60% milled rice which is 20.83 lbs of brown rice. From above, 20.83 lbs of brown rice and using our 65% pressing efficiency should produce 2 gallons of genshu sake or 2.3 gallons of standard 16% sake. This is 14 fluid ounces of standard sake per pound of brown rice. And there you have it.

Of course that depends on the specific homebrewer. However, many of us use whatever is handy. We might use a gallon of water with 2 grams of finings… It depends on what seems (to me) to be most natural and easy at the time.

For these posts I try to be consistant, at least within a post. Also, I do tend to favor non-metric for the U.S. audiance. I tend to think that it is better to be consistant with one form that to show both metric and non-metric, what do you think?

I have a very ignorant question about brewing cooking grade mirin as a home experiment. I am a biochemist but not an experienced brewer. Can I experiment with brown rice, or commercial white rice, koji and a sake yeast like #1801?

How would I go about arresting the fermentation stage with alcohol: when, what indicators to use? The industrial processes seem to employ a one-step procedure : rice + koji + spirits.

I have not been able to find how mirin can be made at home; not tosa mirin, just cooking quality.

Mirin is a different beast. It is not fermented with yeast. It is a little confusing because they talk about fermenting it but this is referring to the koji enzymatic activity. Hon-mirin or the traditional mirin is made with sweet glutinous rice, koji and shochu.

The process is to combine sweet glutinous rice, koji, shochu and water. The water is added so that in the end the alcohol percentage by volume is 14%. It may be higher for most of the brew and then adjusted down to 14% at the end. Sweet glutinous rice is available at Asian markets. Anyway, the rice needs to be rinsed thoroughly, then soaked until 25% to 30% uptake of water and then steamed for 40 to 60 minutes. After cooling the steamed rice can be combined with the koji, shochu and water in a container and placed where it can be held at 65F for 2 to 3 months. The brew is stirred regularly throughout the time.

At the end of the 2 to 3 months you need to press the ferment to separate the mirin from the lees. You may need to do this a a couple of rackings or use a fining agent like bentonite to speed the separation of lees from the clearer mirin. The mirin is then matured or aged for about a year. At the end of this period the mirin is filtered and bottled. While doing this at home you can judge the amount of aging you like.

Because there is no yeast fermentation, there is no need to arrest the fermentation. The fermentation above is all about saccharification of as much of the rice as is possible.

While you could experiment with brown rice I think it will be hard to find brown sweet glutinous rice and I would stick to using this rice until you get comfortable with the process. Depending on where you live, the shochu may be the hardest ingredient to find and will most likely be the most expensive.

For a 1 US Gallon batch you could try something like:
6 lbs sweet glutinous rice
20 oz. koji
3 x 750ml bottles of 25% ABV shochu (sweet potato shochu seems to be the most popular)
9 cups of water

You mention yeast #1801, do you have a source for this yeast? It is a good yeast for ginjo and daiginjo sake.

If you make this I would be very interested in following your progress

Thank you very much for clearing up a great mystery & also simplifying my task. A HUGE THANK YOU. I always wondered about the SINGLE STEP industrial process!!

Re:#18-01, I had gotten that out of the videos linked from this site, may be SakeOne in Oregon speaking of Jokigen Brewery (spelling?) and the specialized yeasts they used [couldn't catch the part about their sister brewery]. I checked Sake World, and they only had up to #15-01 for public sale. Perhaps they could get the other types on demand?

Since I made a major conceptual error regarding mirin production, let me turn my ignorance around and pose a “what if” question suppose you take sake fermentation halfway through, say to 8% alchohol, or a bit more, enough to express some of the sake yeast fruit & aromatics. With enough residual sugars left for sweetness, you add spirits to kill fermentation & amazake to balance sugars. Let everything mellow out, and filter. Do you get a better quality mirin-like substance, a madeira equivalent?

I am fascinated by mirin in Japanese cooking, because it seems to be paired always with sake, and both are subjected to a heat-mediated “alcohol banishing” step. That banishes the more delicate aromas in the sake/mirin combines as well, the same problem faced by wine reductions in sauces. Sort of defeats the whole purpose, in my eyes, at least!

PURPOSE: Sake mash, which is made by a usual method, is combined with an enzyme preparation and steamed rice to effect saccharification and aging, thus producing “mirin”-like sake containing more than 10W11% ethanol and more than 35W 36% saccharides.

CONSTITUTION: Rice and “koji” (malted rice) are used to prepare “sake” mash by a method and the sake mash is combined with an enzyme preparation mainly containing α-amylase, when necessary, additionally glucoamylase, and at least one of steamed rice, sugar, α-form rice or malted rice. Then, the saccharification and aging are effected at 20W30°C.

Have you tried looking around for very sweet sake. It may be close to what your describing. It will not reach the sugar levels of mirin and the added alcohol will thin it but you could give it a try and see what you get.